Azine cyan color formers



United States Patent AZINE CYAN COLOR FORMERS Robert F. Coles, Vestal, and Vsevolod Tulagin, Binghamton, N. Y., assignors to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application November 18, 1955 Serial No. 547,866

6 Claims. (Cl. 96-55) The present invention relates to azine cyan color formers of the J-acid type in which the nitrogen atom in the 6- position of J-acid is converted to a tertiary amino group by the introduction of a benzyl group on the one hand and an aryl or another benzyl group on the other hand.

U. S. Patent 2,486,440, granted November 1, 1949, to W. A. Schmidt and V. Tulagin describes the formation of azine dye images in photographic elements by developing such elements in the presence of a color former with a 2,4-diamino aniline, preferably a 4,6-diamino metanilic acid. Among the color formers suggested for formation of a cyan azine dye image there is mentioned 6-anilino-lnaphthol-3-sulfonic acid. This acid, because of its structure would appear to be suitable for use as a cyan azine color former, but research has established certain objections to this compound for such purposes. Elforts were made to overcome these difficulties by modification of the structure of the aryl J-acids, and these are reported in U. S. Patent 2,480,815 granted August 30, 1949, to V. Tulagin and W. A. Schmidt and U. S. Patent 2,591,642 granted April 1, 1952, to V. Tulagin and R. F. Coles.

The J-acid derivatives of the latter patent, while constituting a decided improvement over the prior compounds, nevertheless, suffered as all previously employed J-acids had from the disadvantage that the cyan dyes obtained therewith are deficient in the desirable green portion of the spectrum.

Considerable attention has been devoted to procuring cyan azine color formers which would exhibit an increased brilliance and a greater green transmission than those heretofore employed. As a result of this study, we have found that compounds more closely approximating these prerequisites can be obtained by introducing a benzyl group on the amino nitrogen in the 6-position of N-monoaryl J -acids or by disubstitution of the amino group in 6- amino-l-naphthol-3-sulfonic acid by a benzyl group.

Such color formers, the preparation of light sensitive color materials containing the same and the processing of such color materials constitute the purposes and objects of the present invention.

The color formers, whose preparation and use are contemplated herein, are represented by the following structural formula:

, or quinoline series, Z in the above formula corresponding to character A in the compounds described in our prior U. S. Patent 2,591,642. Such radical of aromatic character may be, for instance, a ph-enyl radical, i. e., phenyl; toluyl; carboxyphenyl; alkylcarbamylphenyl, i. e., methylcarbamylphenyl, tetradecylcarbamylphenyl, heptadecylcarbamylphenyl; arylcarbamylphenyl, i. e., phenylcarbamylphenyl, toluylcarbamylphenyl, tridecanoylaminophenylcarbamylphenyl, tetradecanoylaminotoluylcarbamylphenyl; a naphthyl radical, i. e., naphthyl; carboxynaphthyl; alkylcarbamylnaphthyl, i. e., dodecylcarbamylnaphthyl; alkylcarbamylalkoxynaphthyl, i. e., octadecylcarbamylmethoxynaphthyl; a pyridyl radical, i. e., pyridyl;

a quinolyl radical, i. e., quinolyl; alkylcarbamylquinolyl, i. e., octadecylcarbamylquinolyl and the like, and R is hydrogen or an alkali metal, such as sodium, potassium or the like.

It is to be pointed out that if the color formers are to be used in the photographic emulsion, then either A or Z must contain an aliphatic radical having a chain of at least 10 carbon atoms, or an aromatic radical containing an aliphatic chain of at least 10 carbon atoms. On the other hand, if the color formers are to be used in the azine developer, then they should be free from such long aliphatic chains to facilitate their diffusion from the developer into the emulsion.

Examples of compounds embraced by the above general formula, and which we have found to partake of the aforesaid prerequisites are the following:

6-[ (N-p-nitrobenzyl,N-benzyl amino]-1-naphthol-3-su1fonic aci 6-[ (N-p-aminob enzyLN-benzyl 3.1111110] -1-naphthol-3-sulfonic N01 s-t (N-p-nitrobenzyLN-B-naphthyl) amindl-l-naphthbl-Fisulfonic acid N SOaH (EH2 6-[N-4'-(1-octadecy1-5-su1fo-2-benzimidazyl) phenylcarbamylbenzyl,N-benzylamino]-l-na.pl1tho1-3su1fon1c acid The following examples will serve to illustrate the invention, although it is to be understood that the invention is not restricted thereto.

PREPARATION OF BENZYL-J ACIDS EXAMPLE I v 6- (N -p-nitr0benzyl, N-benzyl) amino] -1-naphthol-3- sulfonic acid A mixture of benzyl-I-acid (33.2 grams) sodium acetate (33 grams) and water (150 ml.) was placed in a 500 ml. 3-necked flask, equipped with a stirrer and reflux condenser. After heating to near reflux, p-nitrobenzylbromide (22 grams)v was added and the heating continued for -20 minutes. The solution was acidified with hydrochloric acid and the solid collected by filtration. The nearly dry product was suspended in hot methanol (400 ml.) and treated with potassium acetate until dissolved. After cooling, the solid was collected by filtration and washed with fresh methanol in which the potassium salt was now quiteinsoluble. The product was then recrystallized from water containing a small amount of potassium acetate to yield 22 grams of purified material.

EXAMPLE II 6- (N -p-amin0benzyl, N -benzyl amino] -1 -naph th0l-3- sulfonic acid This product was obtained from Example I by reduction with hot alkaline sodium hydrosulfite.

EXAMPLE III 6- (N -p-nitrobenzyl, N -/8-naphthyl amino] -1 naphth0l-3-salf0nic acid A mixture of fl-naphthyl-J-acid, sodium salt (18 grams) sodium acetate (16.4 grams) glacial acetic acid (9.5 ml.) and water (150 ml.) was heated to near reflux in a 500 ml. 3-necked flask, equipped with a stirrer and condenser. p-Nitrobenzylbromide (11 grams) were added and the mixture heated at reflux for 1 hour. An additional 3 grams of the bromide were added and after an additional /2 hour at reflux, the reaction mixture was filtered hot. The gum which separated on cooling the filtrate was collected by decanting the supernatant liquid and then redissolved in 150 m1. hot water. After cooling to room temperature, the solution was filtered from the small amount of crystalline organic material and the filtrate acidified to pH 1 with hydrochloric acid. The

resulting gummy solid Was triturated with 6 N hydro chloric acid and the solid collected. After sucking the solid as dry as possible on a Buchner funnel, the solid was extracted with 50 ml. of hot methanol. The residual solid was dissolved in hot water with the aid of an excess of sodium acetate. Brine was added and the crystalline sodium salt collected.

EXAMPLE IV ml. of water. After heating to reflux, p-carboxybenzylbromide (10.6 grams) was added and the heating continued for 2 hours. The gum obtained after cooling and treating with 30% brine solution was redissolved in 150 ml. of hot water and the solution strongly acidified with .6 N hydrochloric acid. The solid was collected by filtration and extracted with methanol. Purification was finally effected by dissolving the product in hot water with the aid of sodium acetate and allowing to cool after the addition of sufficient brine to induce crystallization. The white crystalline solid was collected by filtration, washed with acetone and dried.

EXAMPLE V w- [N-benzyl-N-2- (S-hydr0xy-7-sulfonaphthyl) amino] p-tolaoylhexadecylamine In a 500 ml. 3-necked flask, equipped with a stirrer, dropping funnel, and reflux condenser fitted with a water take-oiftube, was placed a mixture of the J-acid derivative ofExample IV (8.75 grams) hexadecylamine (3.6 grams) dry pyridine (75 ml.) and dry benzene (35 ml.). The resulting solution was dried by heating at reflux for /2 hour. Phosphorus trichloride (0.7 ml.) in 20 ml. of dry benzene was added dropwise at reflux while stirring. The benzene was removed by the water take-off trap at reflux and the residual solution heated for an additional 3 hours. The remaining solvent was then removed at reduced pressure until a thin syrup remained which was then poured into ice and Water and acidified with acetic acid. The waxy material was separated from the liquor, extracted with dilute acetic acid and brine added to coagulate the material. The solid was then extracted with acetone, dissolved in about 75 ml. of glacial acetic acid, filtered and the filtrate diluted to 300 ml. with water. The product was collected by filtration, extracted with acetone and dried.

EXAMPLE VI 6-[ (N-p-carbovcyphenyl, N-benzyDaminoJ-I- naphthol-3-sulf0nic acid This product was prepared in the same manner as the compound of Example III, while substituting p-carboxyphenyl-J-acid for fi-naphthyl-I-acid, and benzylbromide for p-nitrobenzylbromide.

EXAMPLE VII 6-[(N-p-carbo.acybenzyl, N-phenyl)amin0]-I- naphth0l-3-sulfonic acid This product was prepared in the same manner as the 6-l(N-p-octadecylcarbamylphenyl, N-benzyl)aminl- 1 naphthol-S-sulfonic acid This product was obtained inthe'same manneras that" of Example V, while substituting 6-[(N-p-carboxyphenyl, N-benzyl)amino]-1-naphthol-3-sulfonic acid for the I-acid derivative of Example IV and octadecylamine for hexadecylamine.

EXAMPLE X 6 [(N p (6 tetradecanoylamino 4' sulfa 2'- t0lylcarbamyl)benzyl, N phenyDamino] 1 naphth0l-3-sulfonic acid This product was prepared in the same manner as that of Example V, while substituting 2-amino-6-tetradecanoylamino-toluene-4-sulfonic acid for hexadecylamine, and the product from Example VIII for the J-acid derivative of Example IV.

EXAMPLE XI 6-[(N-6'-carb0xynaphthyl, N-benzyl)aminol-I-naphthol- 3-sulfonic acid This product was prepared in the same manner as that of Example III, while. using 6-carboXynaphthyl-J -ac1d and benzylbromide.-

EXAMPLE XII 6- E (N-p-carboxybenzyl, N-fi-naphthyl) amino] -1-naphth0l-3-sulf0nic acid This product was prepared in the same manner as that of Example IV, with'the substitution of fi-naphthyl J-acid for benzyl-J-acid.

EXAMPLE XIII 6 [N (6(6"-tetradecan0ylamin0-4"-sulf0-2-tolylcarbamyl) 2 naphthyl, N-benzyl)amin0]-1-naphth0l-3- salfonic acid This product was prepared from the product of Example XI and 6-tetradecanoylamino-2-aminotoluene-4- sulfonic acid. by a phosphazo reaction with phosphorus trichloride indry pyridine (see U. S. P. 2,508,860 granted May 23, 1950).

EXAMPLE XIV 6-[(N-p-octadecylcarbamylbenzyl, N-fl-naphthynamino] 1-naphth0l-3-sulf0nic acid Thisnproduct was prepared from the product from Example XII while using the method of Example V and substituting octadecylamine for hexadecylamine.

USE OF NON-DIFFUSING COLOR FORMERS IN SILVER HALIDE EMULSIONS EXAMPLE XV A photographic silver halide emulsion containing per kilo of emulsion grams of the color former of EX- ample V is exposed, the latent image developed in a Metol-hydroquinone developer, re-exposed, and the residual silver halide developed for 10 minutes in a solution of the following composition:

Potassium carbonate grams Sodium sulfite do 60 Ethylene diamine cc 4 (/8 hydroxyethylamino) G-phenylamino-metanilic acid -s grams 3 Water cc 1000 The developer silver. images are bleached with potas sium ferricyanide and fixed in an acid hardening hypo solution. There is thus obtained a'brilliantcyan azine dye.

EXAMPLE XVI An integral tripack having as the bottom layer a red sensitive emulsion containing as the cyan color former the product of Example XIII, as the middle layer a green sensitive emulsion containing as the magenta color former 2-stearoylamino-6- 8-hydroxycinchinoylamino) -tol uene-4-sulfonic acid, and as the outermost layer a blue sensitive emulsion containing asthe yellow color former 2 (benzoylacetamidophenyl) 1-octadecyl-5-benzimidaf zole sulfonic acid, was exposed, developed in black and white, re-eXposed and the residual silver halide developed for 12 minutes in a developer of the following composition:

4 (B hydroxyethylamino) 6-phenylaminometa- The film after development is Washed, bleached in a ferricyanide bleach, and fixed in an acid hardening hypo solution. There is thus obtained a positive dyestufi image in each of the three layers-a brilliant cyan .dye image in the bottom layer, a magenta dye image in the middle layer, and a yellow dye image in the top layer.

Various modifications of the invention will occur to persons skilled in the art and we, therefore, do not intend to be limited in the patent granted except as necessitated by the appended claims.

We claim:

1. A photographic silver halide emulsion containing as a color former fastto .dilfusion a compound of the following formula:

wherein A is a benzyl radical, Z is a radical selected from the class consisting of a benzyl radical and those of the benzene, naphthalene, pyridine and quinoline series, and

R is selected from the class consistingof hydrogen and developing with a 2,4-diamino aniline developer an.ex-.

posed silver halide emulsion in the presence of a color former of the following formula:

wherein A is a benzyl radical, Z is a radical selected from the class consisting ,of a benzyl radical and those" of the benzene, naphthalene, pyridine and quinoline series, and R is selected from the class consisting of hydrogen and a cationic salt forming group.

4. The composition as defined in claim 1, wherein the color former is w-[N-benzyl-N-2-(5-hydroxy-7-sulfonaphthyl) amino] -p{oluoyl-hexadecylamine.

5. The composition as. defined in claim: 1,..wherein;the;

7 9 color former is 6 [N-(6'(6"-tetradecanoylamino-4"-sul- References Cited in the file of this patent fo 2" tolylcarbamyD-Z-naphthyl, N-benzyl) aminoJ-l- FOREIGN PATENTS naphthol-3-sulfonic acid.

6. The composition as defined in claim 1; wherein the 640,109 Great R P July 1950 color former is 6-[N-4-(1-octadecyl-S-sulfo-2-benzimi- 5 691389 Great Bmam May 1953 dazyDphenylcarbamylbenzyl, N benzylamino] l-naphthol-3-sulfonic acid.

UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 2,871,120 January 27, 1959 Robert F. Coles et a].

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4:, lines 15 to 31, Formula (10) should appear as shown below instead of as in the patent:

on @N@-a0m 0.1: Signed and sealed this 23rd day of June 1959.

Attest: KARL H. LAXLINE, ROBERT C. WATSON, Atteating Qfiaez. 10f Patgnh. 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING AS A COLOR FORMER FAST TO DIFFUSIONA COMPOUND OF THE FOLLOWING FORMULA: 